KONGL, SV, VET. AKADEMIEN8 HANDLINGAE. JUAND 26. N:a 2. 



1.55 



This species is remarkable for its arcuate valves, but in its essential characteristics seems 

 to be nearest allied to N. plicata. 



46. N. suavis Cl. and Grove N. Sp. — V. elliptic-lanceolate, flat. L. 0,115; B. 0,o4 

 mm. Axial area very narrow. Central area small, rounded. Median line ending close at the 

 margin. Strise 18 in 0,oi mm. equidistant throughout, iinely punctate; puncta about 18 in 

 0,0 1 mm., somewhat coarser around the central nodule, forming undulating longitudinal row^s. — 

 PI. Ill f. 31, 32. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



47. N. plicatula Grun. Ms. — V. elliptic-lanceolate, with subacute ends, convex, with a 

 more or less distinct longitudinal depression on each side of the median line. L. 0,0 7 5 to 0,115; 

 B. 0,02 to 0,025 mm. Median line with approximate central pores and small terminal nodules at 

 the ends of the valve, flexuose. Areas indistinct. Strise 15 to 19 in 0,oi mm. at the middle, 

 slightly divergent, and 18 to 20 in 0,oi mm. at the ends, parallel, and finely, but distinctly 

 punctate. — PL III f. 28. 



Marine: Gulf of Naples! Balearic Islands! Madagascar! Seychelles! Japan (Brun Coll.)! 

 This is a very characteristic species, remarkable for its undulating median line. 



48. N. inelegaiis Grove and Sturt (1887). — V. lanceolate, gradually tapering from the 

 middle to the somewhat obtuse ends, where are short transverse diaphragms. L. 0,i8; B. 0,o3 mm. 

 Median line with elongated central nodule and small terminal nodules at the ends of the valve. 

 Terminal fissures indistinct. Areas indistinct. Stripe 13 in 0,oi mm. radiate at the ends, some- 

 times crossed on each side of the central nodule by a short and narrow lateral area, punctate; 

 puncta, about 15 in 0,oi mm., forming undulating longitudinal rows. — Grove and Sturt Q. 

 M. Cl. J. Ill p. 132 PL X f. 6. Icon. n. PL V f. 16. 



Marine: Oamaru, New Zealand, fossil! 



This species is a very characteristic form, remarkable for the diaphragms in the ends, as in 

 Pleurostauron. It bears some resemblance to N. Kappa of the same habitat. 



49. N. (Scoliopleura) tuniida Br^b. (1849). — V. lanceolate, gradually attenuated to the 

 subacute ends. L. 0,i to 0,i6; B. 0,025 mm. Median line slightly sigmoid. Axial area very 

 narrow; central area small, somewhat elongated. Striae 13 to 14 in 



0,01 mm., in the middle where a few frequently are shorter than 

 the others, more distant, slightly radiate (at the ends transverse) 

 finely punctate. Frustule in the zonal-view rectangular with rounded 

 angles. Connecting zone slightly oblique, not complex. — Br^b. in 

 Ktitz. Sp. Alg. p. 77. N. Jennerii W. Sm. B. D. I p. 49 PL XVI 

 f. 134 (1853). Scoliopleura tumida V. H. Syn. p. 112 PL XVII 

 f. 11. 13. Pant. Ill PL XVII f. 245. 



Marine and brackish: Franz Josephs Land (Grun.), North 

 Sea! Sebastopol! Ceylon! Sydney! 



Var. adriatica Grun. (1860). — V. 0,027; B. 0,oo8 mm. Me- 

 dian line strongly sigmoid. Striae 12 in 0,oi mm. — Scoliopleura 

 adriatica Grun. Verb. 1860 p. 554 PL V f. 24. 



Marine: Adriatic (Grun.). 



I have seen a few living specimens of N. tumida. They had 

 along the zone two chromatophore-plates, with entire margins. Each 

 plate contained a row of 6 large, orbicular pyrenoids. At the ends 

 of the frustules a number of small granules in Uvely motion was ^^^ ^^^^.^^ ^.^^ cell-contents 500 

 visible. -■ times magnified. 



